This invention relates to the joining of roof or wall panels and the firm attachment of them to a rigid substrate while providing a temperature and moisture seal at the joints. More particularly, the invention relates to an uncomplicated means of providing a secure, sealed joint between construction panels.
The effective and efficient installation of panels to cover and insulate exterior walls and roofs of buildings presents several problems. First of all, it is desirable to minimize the number of steps to install the panels. It must not require an inordinate amount of time to properly align the panels for installation. The amount of equipment necessary to install panels should ideally, be no more than a hammer or screwdriver.
Additionally, the system used for installing the panels should be economical. Waste due to errors in installation, additional cost due to special design or rigid specification requirements for the panels, and specially designed panels rendered unusable due to edge damage in transit should be minimized by the system used for installation.
Obviously, the cost of the devices and materials used for installation of panels should be low. This, however, must be balanced with the system's effectiveness. The system used, besides being easy to install and economical, must provide secure attachment to the roof or wall and an effective seal against moisture and temperature transfer, at the joints formed by abutting panels. The means of attachment must resist loosening of panels through wind action or thermal expansion-contraction. Furthermore, the seal must prevent the transfer of external moisture and the accumulation of internal condensation; the seal must be maintained when the panels contract or shift slightly.
No one system has previously provided solutions to all of the enumerated problems. Some of the systems provided an adequate seal but required the panels to be attached by other means. These required additional steps in the installation of panels. A common method was to insert a liquid sealant into the gap between abutting panels and then cover the joint with a protective tape. In addition to the extra, time-consuming steps involved, the work was delayed because, typically, the sealant had to cure before workers could traverse the joints. Also, there was no way to insure adequate, uniform application of the sealant because of variation in the experience and skill of the workmen installing the roof. Furthermore, the sealant would deteriorate due to exposure to the weather thus requiring use of a protective tape which was susceptible to damage from workers walking on it. To overcome the latter disadvantage, some systems provided a thermoplastic insert which covered the sealant. In combination with the sealant, the thermoplastic cover provided a reasonably effective seal, but the installation was still hampered by the extra steps required and the additional equipment necessary to insert the sealant.
Many of the previous systems required specially designed panels with edges containing rabbets, grooves, extended flanges, or channels for the insertion of part of the sealing or joining system. In addition to the extra cost of the panels, they required extra care in transport and installation to preclude damage to their edges. The panels which required the insertion of part of the system in the panel edge prior to their installation were uneconomical and inefficient due to the extra, time-consuming step.
Some of the systems previously used required a specially designed substrate having grooves along the line where the panels would abut. Besides the increased cost of this construction, the installation of the panels was made more difficult as the panels had to be aligned with the pre-placed grooves.
Many of the systems which purported to provide a moisture seal at the joints were not effective due to gaps remaining under the sealant where condensation could accumulate. Furthermore, most of the moisture seal systems made no provision for a thermal seal. If the panels were installed on a thermal conductive substrate for insulation purposes, the insulation was much less effective due to thermal conduction at the panel joints.
Some prior art systems designed to join panels and attach them to substrates had design defects which permitted loosening of the panels due to wind action or thermal contraction. Besides leaving the panels loose, the system becomes ineffective as a seal since the sealant used, if any, was not flexible enough to compensate for the movement of the panels.
Many of the previously used systems were designed only for use with panels of uniform thickness. Panels manufactured to meet rigid wall thickness specification requirements for use in such systems are necessarily more expensive. Furthermore, if panels of different thicknesses were installed, the joint was not secure nor properly sealed.
Simplicity of installation was another factor not considered by many of the previous systems. The more complicated the system or the more exact the installation had to be the greater likelihood that the average worker would improperly install it. An example of such a system is the type which required the placing of a solidified strip of sealant material over the panel joint before inserting the top part of the system into the receiving part located between the edges of the abutting panels. This system required accurate alignment of the sealant strip and correct insertion of the top part through the sealant into the receiving part. Were the sealant strip misaligned, the seal would be ineffective. Furthermore, once the top part was inserted, it was difficult, if not impossible, to remove it to realign the sealant.
Also, in the prior art, there are many systems designed only for internal and/or temporary use which are not adaptable for permanent use as an attaching and sealing system for exterior roof and wall panels.